I left it at the defaults, which I think is 20. It takes so long to regenerate that I've decided to keep running as it is than spend ages tweaking it.

The MCP changes how screenshots work. There's a checkbox somewhere in the setup menu and that you can change the key that does it, but for me it defaulted to good old PrtScn. I think there's an option to change it from png to something else, but my memory may be faulty there.